[mirror_ubuntu-focal-kernel.git] / drivers / net / wireless / ralink / rt2x00 / rt2x00dev.c

/*
        Copyright (C) 2010 Willow Garage <http://www.willowgarage.com>
        Copyright (C) 2004 - 2010 Ivo van Doorn <IvDoorn@gmail.com>
        <http://rt2x00.serialmonkey.com>

        This program is free software; you can redistribute it and/or modify
        it under the terms of the GNU General Public License as published by
        the Free Software Foundation; either version 2 of the License, or
        (at your option) any later version.

        This program is distributed in the hope that it will be useful,
        but WITHOUT ANY WARRANTY; without even the implied warranty of
        MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
        GNU General Public License for more details.

        You should have received a copy of the GNU General Public License
        along with this program; if not, see <http://www.gnu.org/licenses/>.
 */

/*
        Module: rt2x00lib
        Abstract: rt2x00 generic device routines.
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/log2.h>
#include <linux/of.h>
#include <linux/of_net.h>

#include "rt2x00.h"
#include "rt2x00lib.h"

/*
 * Utility functions.
 */
u32 rt2x00lib_get_bssidx(struct rt2x00_dev *rt2x00dev,
                         struct ieee80211_vif *vif)
{
        /*
         * When in STA mode, bssidx is always 0 otherwise local_address[5]
         * contains the bss number, see BSS_ID_MASK comments for details.
         */
        if (rt2x00dev->intf_sta_count)
                return 0;
        return vif->addr[5] & (rt2x00dev->ops->max_ap_intf - 1);
}
EXPORT_SYMBOL_GPL(rt2x00lib_get_bssidx);

/*
 * Radio control handlers.
 */
int rt2x00lib_enable_radio(struct rt2x00_dev *rt2x00dev)
{
        int status;

        /*
         * Don't enable the radio twice.
         * And check if the hardware button has been disabled.
         */
        if (test_bit(DEVICE_STATE_ENABLED_RADIO, &rt2x00dev->flags))
                return 0;

        /*
         * Initialize all data queues.
         */
        rt2x00queue_init_queues(rt2x00dev);

        /*
         * Enable radio.
         */
        status =
            rt2x00dev->ops->lib->set_device_state(rt2x00dev, STATE_RADIO_ON);
        if (status)
                return status;

        rt2x00dev->ops->lib->set_device_state(rt2x00dev, STATE_RADIO_IRQ_ON);

        rt2x00leds_led_radio(rt2x00dev, true);
        rt2x00led_led_activity(rt2x00dev, true);

        set_bit(DEVICE_STATE_ENABLED_RADIO, &rt2x00dev->flags);

        /*
         * Enable queues.
         */
        rt2x00queue_start_queues(rt2x00dev);
        rt2x00link_start_tuner(rt2x00dev);

        /*
         * Start watchdog monitoring.
         */
        rt2x00link_start_watchdog(rt2x00dev);

        return 0;
}

void rt2x00lib_disable_radio(struct rt2x00_dev *rt2x00dev)
{
        if (!test_and_clear_bit(DEVICE_STATE_ENABLED_RADIO, &rt2x00dev->flags))
                return;

        /*
         * Stop watchdog monitoring.
         */
        rt2x00link_stop_watchdog(rt2x00dev);

        /*
         * Stop all queues
         */
        rt2x00link_stop_tuner(rt2x00dev);
        rt2x00queue_stop_queues(rt2x00dev);
        rt2x00queue_flush_queues(rt2x00dev, true);

        /*
         * Disable radio.
         */
        rt2x00dev->ops->lib->set_device_state(rt2x00dev, STATE_RADIO_OFF);
        rt2x00dev->ops->lib->set_device_state(rt2x00dev, STATE_RADIO_IRQ_OFF);
        rt2x00led_led_activity(rt2x00dev, false);
        rt2x00leds_led_radio(rt2x00dev, false);
}

static void rt2x00lib_intf_scheduled_iter(void *data, u8 *mac,
                                          struct ieee80211_vif *vif)
{
        struct rt2x00_dev *rt2x00dev = data;
        struct rt2x00_intf *intf = vif_to_intf(vif);

        /*
         * It is possible the radio was disabled while the work had been
         * scheduled. If that happens we should return here immediately,
         * note that in the spinlock protected area above the delayed_flags
         * have been cleared correctly.
         */
        if (!test_bit(DEVICE_STATE_ENABLED_RADIO, &rt2x00dev->flags))
                return;

        if (test_and_clear_bit(DELAYED_UPDATE_BEACON, &intf->delayed_flags)) {
                mutex_lock(&intf->beacon_skb_mutex);
                rt2x00queue_update_beacon(rt2x00dev, vif);
                mutex_unlock(&intf->beacon_skb_mutex);
        }
}

static void rt2x00lib_intf_scheduled(struct work_struct *work)
{
        struct rt2x00_dev *rt2x00dev =
            container_of(work, struct rt2x00_dev, intf_work);

        /*
         * Iterate over each interface and perform the
         * requested configurations.
         */
        ieee80211_iterate_active_interfaces(rt2x00dev->hw,
                                            IEEE80211_IFACE_ITER_RESUME_ALL,
                                            rt2x00lib_intf_scheduled_iter,
                                            rt2x00dev);
}

static void rt2x00lib_autowakeup(struct work_struct *work)
{
        struct rt2x00_dev *rt2x00dev =
            container_of(work, struct rt2x00_dev, autowakeup_work.work);

        if (!test_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags))
                return;

        if (rt2x00dev->ops->lib->set_device_state(rt2x00dev, STATE_AWAKE))
                rt2x00_err(rt2x00dev, "Device failed to wakeup\n");
        clear_bit(CONFIG_POWERSAVING, &rt2x00dev->flags);
}

/*
 * Interrupt context handlers.
 */
static void rt2x00lib_bc_buffer_iter(void *data, u8 *mac,
                                     struct ieee80211_vif *vif)
{
        struct ieee80211_tx_control control = {};
        struct rt2x00_dev *rt2x00dev = data;
        struct sk_buff *skb;

        /*
         * Only AP mode interfaces do broad- and multicast buffering
         */
        if (vif->type != NL80211_IFTYPE_AP)
                return;

        /*
         * Send out buffered broad- and multicast frames
         */
        skb = ieee80211_get_buffered_bc(rt2x00dev->hw, vif);
        while (skb) {
                rt2x00mac_tx(rt2x00dev->hw, &control, skb);
                skb = ieee80211_get_buffered_bc(rt2x00dev->hw, vif);
        }
}

static void rt2x00lib_beaconupdate_iter(void *data, u8 *mac,
                                        struct ieee80211_vif *vif)
{
        struct rt2x00_dev *rt2x00dev = data;

        if (vif->type != NL80211_IFTYPE_AP &&
            vif->type != NL80211_IFTYPE_ADHOC &&
            vif->type != NL80211_IFTYPE_MESH_POINT &&
            vif->type != NL80211_IFTYPE_WDS)
                return;

        /*
         * Update the beacon without locking. This is safe on PCI devices
         * as they only update the beacon periodically here. This should
         * never be called for USB devices.
         */
        WARN_ON(rt2x00_is_usb(rt2x00dev));
        rt2x00queue_update_beacon(rt2x00dev, vif);
}

void rt2x00lib_beacondone(struct rt2x00_dev *rt2x00dev)
{
        if (!test_bit(DEVICE_STATE_ENABLED_RADIO, &rt2x00dev->flags))
                return;

        /* send buffered bc/mc frames out for every bssid */
        ieee80211_iterate_active_interfaces_atomic(
                rt2x00dev->hw, IEEE80211_IFACE_ITER_RESUME_ALL,
                rt2x00lib_bc_buffer_iter, rt2x00dev);
        /*
         * Devices with pre tbtt interrupt don't need to update the beacon
         * here as they will fetch the next beacon directly prior to
         * transmission.
         */
        if (rt2x00_has_cap_pre_tbtt_interrupt(rt2x00dev))
                return;

        /* fetch next beacon */
        ieee80211_iterate_active_interfaces_atomic(
                rt2x00dev->hw, IEEE80211_IFACE_ITER_RESUME_ALL,
                rt2x00lib_beaconupdate_iter, rt2x00dev);
}
EXPORT_SYMBOL_GPL(rt2x00lib_beacondone);

void rt2x00lib_pretbtt(struct rt2x00_dev *rt2x00dev)
{
        if (!test_bit(DEVICE_STATE_ENABLED_RADIO, &rt2x00dev->flags))
                return;

        /* fetch next beacon */
        ieee80211_iterate_active_interfaces_atomic(
                rt2x00dev->hw, IEEE80211_IFACE_ITER_RESUME_ALL,
                rt2x00lib_beaconupdate_iter, rt2x00dev);
}
EXPORT_SYMBOL_GPL(rt2x00lib_pretbtt);

void rt2x00lib_dmastart(struct queue_entry *entry)
{
        set_bit(ENTRY_OWNER_DEVICE_DATA, &entry->flags);
        rt2x00queue_index_inc(entry, Q_INDEX);
}
EXPORT_SYMBOL_GPL(rt2x00lib_dmastart);

void rt2x00lib_dmadone(struct queue_entry *entry)
{
        set_bit(ENTRY_DATA_STATUS_PENDING, &entry->flags);
        clear_bit(ENTRY_OWNER_DEVICE_DATA, &entry->flags);
        rt2x00queue_index_inc(entry, Q_INDEX_DMA_DONE);
}
EXPORT_SYMBOL_GPL(rt2x00lib_dmadone);

static inline int rt2x00lib_txdone_bar_status(struct queue_entry *entry)
{
        struct rt2x00_dev *rt2x00dev = entry->queue->rt2x00dev;
        struct ieee80211_bar *bar = (void *) entry->skb->data;
        struct rt2x00_bar_list_entry *bar_entry;
        int ret;

        if (likely(!ieee80211_is_back_req(bar->frame_control)))
                return 0;

        /*
         * Unlike all other frames, the status report for BARs does
         * not directly come from the hardware as it is incapable of
         * matching a BA to a previously send BAR. The hardware will
         * report all BARs as if they weren't acked at all.
         *
         * Instead the RX-path will scan for incoming BAs and set the
         * block_acked flag if it sees one that was likely caused by
         * a BAR from us.
         *
         * Remove remaining BARs here and return their status for
         * TX done processing.
         */
        ret = 0;
        rcu_read_lock();
        list_for_each_entry_rcu(bar_entry, &rt2x00dev->bar_list, list) {
                if (bar_entry->entry != entry)
                        continue;

                spin_lock_bh(&rt2x00dev->bar_list_lock);
                /* Return whether this BAR was blockacked or not */
                ret = bar_entry->block_acked;
                /* Remove the BAR from our checklist */
                list_del_rcu(&bar_entry->list);
                spin_unlock_bh(&rt2x00dev->bar_list_lock);
                kfree_rcu(bar_entry, head);

                break;
        }
        rcu_read_unlock();

        return ret;
}

static void rt2x00lib_fill_tx_status(struct rt2x00_dev *rt2x00dev,
                                     struct ieee80211_tx_info *tx_info,
                                     struct skb_frame_desc *skbdesc,
                                     struct txdone_entry_desc *txdesc,
                                     bool success)
{
        u8 rate_idx, rate_flags, retry_rates;
        int i;

        rate_idx = skbdesc->tx_rate_idx;
        rate_flags = skbdesc->tx_rate_flags;
        retry_rates = test_bit(TXDONE_FALLBACK, &txdesc->flags) ?
            (txdesc->retry + 1) : 1;

        /*
         * Initialize TX status
         */
        memset(&tx_info->status, 0, sizeof(tx_info->status));
        tx_info->status.ack_signal = 0;

        /*
         * Frame was send with retries, hardware tried
         * different rates to send out the frame, at each
         * retry it lowered the rate 1 step except when the
         * lowest rate was used.
         */
        for (i = 0; i < retry_rates && i < IEEE80211_TX_MAX_RATES; i++) {
                tx_info->status.rates[i].idx = rate_idx - i;
                tx_info->status.rates[i].flags = rate_flags;

                if (rate_idx - i == 0) {
                        /*
                         * The lowest rate (index 0) was used until the
                         * number of max retries was reached.
                         */
                        tx_info->status.rates[i].count = retry_rates - i;
                        i++;
                        break;
                }
                tx_info->status.rates[i].count = 1;
        }
        if (i < (IEEE80211_TX_MAX_RATES - 1))
                tx_info->status.rates[i].idx = -1; /* terminate */

        if (test_bit(TXDONE_NO_ACK_REQ, &txdesc->flags))
                tx_info->flags |= IEEE80211_TX_CTL_NO_ACK;

        if (!(tx_info->flags & IEEE80211_TX_CTL_NO_ACK)) {
                if (success)
                        tx_info->flags |= IEEE80211_TX_STAT_ACK;
                else
                        rt2x00dev->low_level_stats.dot11ACKFailureCount++;
        }

        /*
         * Every single frame has it's own tx status, hence report
         * every frame as ampdu of size 1.
         *
         * TODO: if we can find out how many frames were aggregated
         * by the hw we could provide the real ampdu_len to mac80211
         * which would allow the rc algorithm to better decide on
         * which rates are suitable.
         */
        if (test_bit(TXDONE_AMPDU, &txdesc->flags) ||
            tx_info->flags & IEEE80211_TX_CTL_AMPDU) {
                tx_info->flags |= IEEE80211_TX_STAT_AMPDU |
                                  IEEE80211_TX_CTL_AMPDU;
                tx_info->status.ampdu_len = 1;
                tx_info->status.ampdu_ack_len = success ? 1 : 0;

                if (!success)
                        tx_info->flags |= IEEE80211_TX_STAT_AMPDU_NO_BACK;
        }

        if (rate_flags & IEEE80211_TX_RC_USE_RTS_CTS) {
                if (success)
                        rt2x00dev->low_level_stats.dot11RTSSuccessCount++;
                else
                        rt2x00dev->low_level_stats.dot11RTSFailureCount++;
        }
}

static void rt2x00lib_clear_entry(struct rt2x00_dev *rt2x00dev,
                                  struct queue_entry *entry)
{
        /*
         * Make this entry available for reuse.
         */
        entry->skb = NULL;
        entry->flags = 0;

        rt2x00dev->ops->lib->clear_entry(entry);

        rt2x00queue_index_inc(entry, Q_INDEX_DONE);

        /*
         * If the data queue was below the threshold before the txdone
         * handler we must make sure the packet queue in the mac80211 stack
         * is reenabled when the txdone handler has finished. This has to be
         * serialized with rt2x00mac_tx(), otherwise we can wake up queue
         * before it was stopped.
         */
        spin_lock_bh(&entry->queue->tx_lock);
        if (!rt2x00queue_threshold(entry->queue))
                rt2x00queue_unpause_queue(entry->queue);
        spin_unlock_bh(&entry->queue->tx_lock);
}

void rt2x00lib_txdone_nomatch(struct queue_entry *entry,
                              struct txdone_entry_desc *txdesc)
{
        struct rt2x00_dev *rt2x00dev = entry->queue->rt2x00dev;
        struct skb_frame_desc *skbdesc = get_skb_frame_desc(entry->skb);
        struct ieee80211_tx_info txinfo = {};
        bool success;

        /*
         * Unmap the skb.
         */
        rt2x00queue_unmap_skb(entry);

        /*
         * Signal that the TX descriptor is no longer in the skb.
         */
        skbdesc->flags &= ~SKBDESC_DESC_IN_SKB;

        /*
         * Send frame to debugfs immediately, after this call is completed
         * we are going to overwrite the skb->cb array.
         */
        rt2x00debug_dump_frame(rt2x00dev, DUMP_FRAME_TXDONE, entry);

        /*
         * Determine if the frame has been successfully transmitted and
         * remove BARs from our check list while checking for their
         * TX status.
         */
        success =
            rt2x00lib_txdone_bar_status(entry) ||
            test_bit(TXDONE_SUCCESS, &txdesc->flags);

        if (!test_bit(TXDONE_UNKNOWN, &txdesc->flags)) {
                /*
                 * Update TX statistics.
                 */
                rt2x00dev->link.qual.tx_success += success;
                rt2x00dev->link.qual.tx_failed += !success;

                rt2x00lib_fill_tx_status(rt2x00dev, &txinfo, skbdesc, txdesc,
                                         success);
                ieee80211_tx_status_noskb(rt2x00dev->hw, skbdesc->sta, &txinfo);
        }

        dev_kfree_skb_any(entry->skb);
        rt2x00lib_clear_entry(rt2x00dev, entry);
}
EXPORT_SYMBOL_GPL(rt2x00lib_txdone_nomatch);

void rt2x00lib_txdone(struct queue_entry *entry,
                      struct txdone_entry_desc *txdesc)
{
        struct rt2x00_dev *rt2x00dev = entry->queue->rt2x00dev;
        struct ieee80211_tx_info *tx_info = IEEE80211_SKB_CB(entry->skb);
        struct skb_frame_desc *skbdesc = get_skb_frame_desc(entry->skb);
        u8 skbdesc_flags = skbdesc->flags;
        unsigned int header_length;
        bool success;

        /*
         * Unmap the skb.
         */
        rt2x00queue_unmap_skb(entry);

        /*
         * Remove the extra tx headroom from the skb.
         */
        skb_pull(entry->skb, rt2x00dev->extra_tx_headroom);

        /*
         * Signal that the TX descriptor is no longer in the skb.
         */
        skbdesc->flags &= ~SKBDESC_DESC_IN_SKB;

        /*
         * Determine the length of 802.11 header.
         */
        header_length = ieee80211_get_hdrlen_from_skb(entry->skb);

        /*
         * Remove L2 padding which was added during
         */
        if (rt2x00_has_cap_flag(rt2x00dev, REQUIRE_L2PAD))
                rt2x00queue_remove_l2pad(entry->skb, header_length);

        /*
         * If the IV/EIV data was stripped from the frame before it was
         * passed to the hardware, we should now reinsert it again because
         * mac80211 will expect the same data to be present it the
         * frame as it was passed to us.
         */
        if (rt2x00_has_cap_hw_crypto(rt2x00dev))
                rt2x00crypto_tx_insert_iv(entry->skb, header_length);

        /*
         * Send frame to debugfs immediately, after this call is completed
         * we are going to overwrite the skb->cb array.
         */
        rt2x00debug_dump_frame(rt2x00dev, DUMP_FRAME_TXDONE, entry);

        /*
         * Determine if the frame has been successfully transmitted and
         * remove BARs from our check list while checking for their
         * TX status.
         */
        success =
            rt2x00lib_txdone_bar_status(entry) ||
            test_bit(TXDONE_SUCCESS, &txdesc->flags) ||
            test_bit(TXDONE_UNKNOWN, &txdesc->flags);

        /*
         * Update TX statistics.
         */
        rt2x00dev->link.qual.tx_success += success;
        rt2x00dev->link.qual.tx_failed += !success;

        rt2x00lib_fill_tx_status(rt2x00dev, tx_info, skbdesc, txdesc, success);

        /*
         * Only send the status report to mac80211 when it's a frame
         * that originated in mac80211. If this was a extra frame coming
         * through a mac80211 library call (RTS/CTS) then we should not
         * send the status report back.
         */
        if (!(skbdesc_flags & SKBDESC_NOT_MAC80211)) {
                if (rt2x00_has_cap_flag(rt2x00dev, REQUIRE_TASKLET_CONTEXT))
                        ieee80211_tx_status(rt2x00dev->hw, entry->skb);
                else
                        ieee80211_tx_status_ni(rt2x00dev->hw, entry->skb);
        } else {
                dev_kfree_skb_any(entry->skb);
        }

        rt2x00lib_clear_entry(rt2x00dev, entry);
}
EXPORT_SYMBOL_GPL(rt2x00lib_txdone);

void rt2x00lib_txdone_noinfo(struct queue_entry *entry, u32 status)
{
        struct txdone_entry_desc txdesc;

        txdesc.flags = 0;
        __set_bit(status, &txdesc.flags);
        txdesc.retry = 0;

        rt2x00lib_txdone(entry, &txdesc);
}
EXPORT_SYMBOL_GPL(rt2x00lib_txdone_noinfo);

static u8 *rt2x00lib_find_ie(u8 *data, unsigned int len, u8 ie)
{
        struct ieee80211_mgmt *mgmt = (void *)data;
        u8 *pos, *end;

        pos = (u8 *)mgmt->u.beacon.variable;
        end = data + len;
        while (pos < end) {
                if (pos + 2 + pos[1] > end)
                        return NULL;

                if (pos[0] == ie)
                        return pos;

                pos += 2 + pos[1];
        }

        return NULL;
}

static void rt2x00lib_sleep(struct work_struct *work)
{
        struct rt2x00_dev *rt2x00dev =
            container_of(work, struct rt2x00_dev, sleep_work);

        if (!test_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags))
                return;

        /*
         * Check again is powersaving is enabled, to prevent races from delayed
         * work execution.
         */
        if (!test_bit(CONFIG_POWERSAVING, &rt2x00dev->flags))
                rt2x00lib_config(rt2x00dev, &rt2x00dev->hw->conf,
                                 IEEE80211_CONF_CHANGE_PS);
}

static void rt2x00lib_rxdone_check_ba(struct rt2x00_dev *rt2x00dev,
                                      struct sk_buff *skb,
                                      struct rxdone_entry_desc *rxdesc)
{
        struct rt2x00_bar_list_entry *entry;
        struct ieee80211_bar *ba = (void *)skb->data;

        if (likely(!ieee80211_is_back(ba->frame_control)))
                return;

        if (rxdesc->size < sizeof(*ba) + FCS_LEN)
                return;

        rcu_read_lock();
        list_for_each_entry_rcu(entry, &rt2x00dev->bar_list, list) {

                if (ba->start_seq_num != entry->start_seq_num)
                        continue;

#define TID_CHECK(a, b) (                                               \
        ((a) & cpu_to_le16(IEEE80211_BAR_CTRL_TID_INFO_MASK)) ==        \
        ((b) & cpu_to_le16(IEEE80211_BAR_CTRL_TID_INFO_MASK)))          \

                if (!TID_CHECK(ba->control, entry->control))
                        continue;

#undef TID_CHECK

                if (!ether_addr_equal_64bits(ba->ra, entry->ta))
                        continue;

                if (!ether_addr_equal_64bits(ba->ta, entry->ra))
                        continue;

                /* Mark BAR since we received the according BA */
                spin_lock_bh(&rt2x00dev->bar_list_lock);
                entry->block_acked = 1;
                spin_unlock_bh(&rt2x00dev->bar_list_lock);
                break;
        }
        rcu_read_unlock();

}

static void rt2x00lib_rxdone_check_ps(struct rt2x00_dev *rt2x00dev,
                                      struct sk_buff *skb,
                                      struct rxdone_entry_desc *rxdesc)
{
        struct ieee80211_hdr *hdr = (void *) skb->data;
        struct ieee80211_tim_ie *tim_ie;
        u8 *tim;
        u8 tim_len;
        bool cam;

        /* If this is not a beacon, or if mac80211 has no powersaving
         * configured, or if the device is already in powersaving mode
         * we can exit now. */
        if (likely(!ieee80211_is_beacon(hdr->frame_control) ||
                   !(rt2x00dev->hw->conf.flags & IEEE80211_CONF_PS)))
                return;

        /* min. beacon length + FCS_LEN */
        if (skb->len <= 40 + FCS_LEN)
                return;

        /* and only beacons from the associated BSSID, please */
        if (!(rxdesc->dev_flags & RXDONE_MY_BSS) ||
            !rt2x00dev->aid)
                return;

        rt2x00dev->last_beacon = jiffies;

        tim = rt2x00lib_find_ie(skb->data, skb->len - FCS_LEN, WLAN_EID_TIM);
        if (!tim)
                return;

        if (tim[1] < sizeof(*tim_ie))
                return;

        tim_len = tim[1];
        tim_ie = (struct ieee80211_tim_ie *) &tim[2];

        /* Check whenever the PHY can be turned off again. */

        /* 1. What about buffered unicast traffic for our AID? */
        cam = ieee80211_check_tim(tim_ie, tim_len, rt2x00dev->aid);

        /* 2. Maybe the AP wants to send multicast/broadcast data? */
        cam |= (tim_ie->bitmap_ctrl & 0x01);

        if (!cam && !test_bit(CONFIG_POWERSAVING, &rt2x00dev->flags))
                queue_work(rt2x00dev->workqueue, &rt2x00dev->sleep_work);
}

static int rt2x00lib_rxdone_read_signal(struct rt2x00_dev *rt2x00dev,
                                        struct rxdone_entry_desc *rxdesc)
{
        struct ieee80211_supported_band *sband;
        const struct rt2x00_rate *rate;
        unsigned int i;
        int signal = rxdesc->signal;
        int type = (rxdesc->dev_flags & RXDONE_SIGNAL_MASK);

        switch (rxdesc->rate_mode) {
        case RATE_MODE_CCK:
        case RATE_MODE_OFDM:
                /*
                 * For non-HT rates the MCS value needs to contain the
                 * actually used rate modulation (CCK or OFDM).
                 */
                if (rxdesc->dev_flags & RXDONE_SIGNAL_MCS)
                        signal = RATE_MCS(rxdesc->rate_mode, signal);

                sband = &rt2x00dev->bands[rt2x00dev->curr_band];
                for (i = 0; i < sband->n_bitrates; i++) {
                        rate = rt2x00_get_rate(sband->bitrates[i].hw_value);
                        if (((type == RXDONE_SIGNAL_PLCP) &&
                             (rate->plcp == signal)) ||
                            ((type == RXDONE_SIGNAL_BITRATE) &&
                              (rate->bitrate == signal)) ||
                            ((type == RXDONE_SIGNAL_MCS) &&
                              (rate->mcs == signal))) {
                                return i;
                        }
                }
                break;
        case RATE_MODE_HT_MIX:
        case RATE_MODE_HT_GREENFIELD:
                if (signal >= 0 && signal <= 76)
                        return signal;
                break;
        default:
                break;
        }

        rt2x00_warn(rt2x00dev, "Frame received with unrecognized signal, mode=0x%.4x, signal=0x%.4x, type=%d\n",
                    rxdesc->rate_mode, signal, type);
        return 0;
}

void rt2x00lib_rxdone(struct queue_entry *entry, gfp_t gfp)
{
        struct rt2x00_dev *rt2x00dev = entry->queue->rt2x00dev;
        struct rxdone_entry_desc rxdesc;
        struct sk_buff *skb;
        struct ieee80211_rx_status *rx_status;
        unsigned int header_length;
        int rate_idx;

        if (!test_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags) ||
            !test_bit(DEVICE_STATE_ENABLED_RADIO, &rt2x00dev->flags))
                goto submit_entry;

        if (test_bit(ENTRY_DATA_IO_FAILED, &entry->flags))
                goto submit_entry;

        /*
         * Allocate a new sk_buffer. If no new buffer available, drop the
         * received frame and reuse the existing buffer.
         */
        skb = rt2x00queue_alloc_rxskb(entry, gfp);
        if (!skb)
                goto submit_entry;

        /*
         * Unmap the skb.
         */
        rt2x00queue_unmap_skb(entry);

        /*
         * Extract the RXD details.
         */
        memset(&rxdesc, 0, sizeof(rxdesc));
        rt2x00dev->ops->lib->fill_rxdone(entry, &rxdesc);

        /*
         * Check for valid size in case we get corrupted descriptor from
         * hardware.
         */
        if (unlikely(rxdesc.size == 0 ||
                     rxdesc.size > entry->queue->data_size)) {
                rt2x00_err(rt2x00dev, "Wrong frame size %d max %d\n",
                           rxdesc.size, entry->queue->data_size);
                dev_kfree_skb(entry->skb);
                goto renew_skb;
        }

        /*
         * The data behind the ieee80211 header must be
         * aligned on a 4 byte boundary.
         */
        header_length = ieee80211_get_hdrlen_from_skb(entry->skb);

        /*
         * Hardware might have stripped the IV/EIV/ICV data,
         * in that case it is possible that the data was
         * provided separately (through hardware descriptor)
         * in which case we should reinsert the data into the frame.
         */
        if ((rxdesc.dev_flags & RXDONE_CRYPTO_IV) &&
            (rxdesc.flags & RX_FLAG_IV_STRIPPED))
                rt2x00crypto_rx_insert_iv(entry->skb, header_length,
                                          &rxdesc);
        else if (header_length &&
                 (rxdesc.size > header_length) &&
                 (rxdesc.dev_flags & RXDONE_L2PAD))
                rt2x00queue_remove_l2pad(entry->skb, header_length);

        /* Trim buffer to correct size */
        skb_trim(entry->skb, rxdesc.size);

        /*
         * Translate the signal to the correct bitrate index.
         */
        rate_idx = rt2x00lib_rxdone_read_signal(rt2x00dev, &rxdesc);
        if (rxdesc.rate_mode == RATE_MODE_HT_MIX ||
            rxdesc.rate_mode == RATE_MODE_HT_GREENFIELD)
                rxdesc.encoding = RX_ENC_HT;

        /*
         * Check if this is a beacon, and more frames have been
         * buffered while we were in powersaving mode.
         */
        rt2x00lib_rxdone_check_ps(rt2x00dev, entry->skb, &rxdesc);

        /*
         * Check for incoming BlockAcks to match to the BlockAckReqs
         * we've send out.
         */
        rt2x00lib_rxdone_check_ba(rt2x00dev, entry->skb, &rxdesc);

        /*
         * Update extra components
         */
        rt2x00link_update_stats(rt2x00dev, entry->skb, &rxdesc);
        rt2x00debug_update_crypto(rt2x00dev, &rxdesc);
        rt2x00debug_dump_frame(rt2x00dev, DUMP_FRAME_RXDONE, entry);

        /*
         * Initialize RX status information, and send frame
         * to mac80211.
         */
        rx_status = IEEE80211_SKB_RXCB(entry->skb);

        /* Ensure that all fields of rx_status are initialized
         * properly. The skb->cb array was used for driver
         * specific informations, so rx_status might contain
         * garbage.
         */
        memset(rx_status, 0, sizeof(*rx_status));

        rx_status->mactime = rxdesc.timestamp;
        rx_status->band = rt2x00dev->curr_band;
        rx_status->freq = rt2x00dev->curr_freq;
        rx_status->rate_idx = rate_idx;
        rx_status->signal = rxdesc.rssi;
        rx_status->flag = rxdesc.flags;
        rx_status->enc_flags = rxdesc.enc_flags;
        rx_status->encoding = rxdesc.encoding;
        rx_status->bw = rxdesc.bw;
        rx_status->antenna = rt2x00dev->link.ant.active.rx;

        ieee80211_rx_ni(rt2x00dev->hw, entry->skb);

renew_skb:
        /*
         * Replace the skb with the freshly allocated one.
         */
        entry->skb = skb;

submit_entry:
        entry->flags = 0;
        rt2x00queue_index_inc(entry, Q_INDEX_DONE);
        if (test_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags) &&
            test_bit(DEVICE_STATE_ENABLED_RADIO, &rt2x00dev->flags))
                rt2x00dev->ops->lib->clear_entry(entry);
}
EXPORT_SYMBOL_GPL(rt2x00lib_rxdone);

/*
 * Driver initialization handlers.
 */
const struct rt2x00_rate rt2x00_supported_rates[12] = {
        {
                .flags = DEV_RATE_CCK,
                .bitrate = 10,
                .ratemask = BIT(0),
                .plcp = 0x00,
                .mcs = RATE_MCS(RATE_MODE_CCK, 0),
        },
        {
                .flags = DEV_RATE_CCK | DEV_RATE_SHORT_PREAMBLE,
                .bitrate = 20,
                .ratemask = BIT(1),
                .plcp = 0x01,
                .mcs = RATE_MCS(RATE_MODE_CCK, 1),
        },
        {
                .flags = DEV_RATE_CCK | DEV_RATE_SHORT_PREAMBLE,
                .bitrate = 55,
                .ratemask = BIT(2),
                .plcp = 0x02,
                .mcs = RATE_MCS(RATE_MODE_CCK, 2),
        },
        {
                .flags = DEV_RATE_CCK | DEV_RATE_SHORT_PREAMBLE,
                .bitrate = 110,
                .ratemask = BIT(3),
                .plcp = 0x03,
                .mcs = RATE_MCS(RATE_MODE_CCK, 3),
        },
        {
                .flags = DEV_RATE_OFDM,
                .bitrate = 60,
                .ratemask = BIT(4),
                .plcp = 0x0b,
                .mcs = RATE_MCS(RATE_MODE_OFDM, 0),
        },
        {
                .flags = DEV_RATE_OFDM,
                .bitrate = 90,
                .ratemask = BIT(5),
                .plcp = 0x0f,
                .mcs = RATE_MCS(RATE_MODE_OFDM, 1),
        },
        {
                .flags = DEV_RATE_OFDM,
                .bitrate = 120,
                .ratemask = BIT(6),
                .plcp = 0x0a,
                .mcs = RATE_MCS(RATE_MODE_OFDM, 2),
        },
        {
                .flags = DEV_RATE_OFDM,
                .bitrate = 180,
                .ratemask = BIT(7),
                .plcp = 0x0e,
                .mcs = RATE_MCS(RATE_MODE_OFDM, 3),
        },
        {
                .flags = DEV_RATE_OFDM,
                .bitrate = 240,
                .ratemask = BIT(8),
                .plcp = 0x09,
                .mcs = RATE_MCS(RATE_MODE_OFDM, 4),
        },
        {
                .flags = DEV_RATE_OFDM,
                .bitrate = 360,
                .ratemask = BIT(9),
                .plcp = 0x0d,
                .mcs = RATE_MCS(RATE_MODE_OFDM, 5),
        },
        {
                .flags = DEV_RATE_OFDM,
                .bitrate = 480,
                .ratemask = BIT(10),
                .plcp = 0x08,
                .mcs = RATE_MCS(RATE_MODE_OFDM, 6),
        },
        {
                .flags = DEV_RATE_OFDM,
                .bitrate = 540,
                .ratemask = BIT(11),
                .plcp = 0x0c,
                .mcs = RATE_MCS(RATE_MODE_OFDM, 7),
        },
};

static void rt2x00lib_channel(struct ieee80211_channel *entry,
                              const int channel, const int tx_power,
                              const int value)
{
        /* XXX: this assumption about the band is wrong for 802.11j */
        entry->band = channel <= 14 ? NL80211_BAND_2GHZ : NL80211_BAND_5GHZ;
        entry->center_freq = ieee80211_channel_to_frequency(channel,
                                                            entry->band);
        entry->hw_value = value;
        entry->max_power = tx_power;
        entry->max_antenna_gain = 0xff;
}

static void rt2x00lib_rate(struct ieee80211_rate *entry,
                           const u16 index, const struct rt2x00_rate *rate)
{
        entry->flags = 0;
        entry->bitrate = rate->bitrate;
        entry->hw_value = index;
        entry->hw_value_short = index;

        if (rate->flags & DEV_RATE_SHORT_PREAMBLE)
                entry->flags |= IEEE80211_RATE_SHORT_PREAMBLE;
}

void rt2x00lib_set_mac_address(struct rt2x00_dev *rt2x00dev, u8 *eeprom_mac_addr)
{
        const char *mac_addr;

        mac_addr = of_get_mac_address(rt2x00dev->dev->of_node);
        if (!IS_ERR(mac_addr))
                ether_addr_copy(eeprom_mac_addr, mac_addr);

        if (!is_valid_ether_addr(eeprom_mac_addr)) {
                eth_random_addr(eeprom_mac_addr);
                rt2x00_eeprom_dbg(rt2x00dev, "MAC: %pM\n", eeprom_mac_addr);
        }
}
EXPORT_SYMBOL_GPL(rt2x00lib_set_mac_address);

static int rt2x00lib_probe_hw_modes(struct rt2x00_dev *rt2x00dev,
                                    struct hw_mode_spec *spec)
{
        struct ieee80211_hw *hw = rt2x00dev->hw;
        struct ieee80211_channel *channels;
        struct ieee80211_rate *rates;
        unsigned int num_rates;
        unsigned int i;

        num_rates = 0;
        if (spec->supported_rates & SUPPORT_RATE_CCK)
                num_rates += 4;
        if (spec->supported_rates & SUPPORT_RATE_OFDM)
                num_rates += 8;

        channels = kcalloc(spec->num_channels, sizeof(*channels), GFP_KERNEL);
        if (!channels)
                return -ENOMEM;

        rates = kcalloc(num_rates, sizeof(*rates), GFP_KERNEL);
        if (!rates)
                goto exit_free_channels;

        /*
         * Initialize Rate list.
         */
        for (i = 0; i < num_rates; i++)
                rt2x00lib_rate(&rates[i], i, rt2x00_get_rate(i));

        /*
         * Initialize Channel list.
         */
        for (i = 0; i < spec->num_channels; i++) {
                rt2x00lib_channel(&channels[i],
                                  spec->channels[i].channel,
                                  spec->channels_info[i].max_power, i);
        }

        /*
         * Intitialize 802.11b, 802.11g
         * Rates: CCK, OFDM.
         * Channels: 2.4 GHz
         */
        if (spec->supported_bands & SUPPORT_BAND_2GHZ) {
                rt2x00dev->bands[NL80211_BAND_2GHZ].n_channels = 14;
                rt2x00dev->bands[NL80211_BAND_2GHZ].n_bitrates = num_rates;
                rt2x00dev->bands[NL80211_BAND_2GHZ].channels = channels;
                rt2x00dev->bands[NL80211_BAND_2GHZ].bitrates = rates;
                hw->wiphy->bands[NL80211_BAND_2GHZ] =
                    &rt2x00dev->bands[NL80211_BAND_2GHZ];
                memcpy(&rt2x00dev->bands[NL80211_BAND_2GHZ].ht_cap,
                       &spec->ht, sizeof(spec->ht));
        }

        /*
         * Intitialize 802.11a
         * Rates: OFDM.
         * Channels: OFDM, UNII, HiperLAN2.
         */
        if (spec->supported_bands & SUPPORT_BAND_5GHZ) {
                rt2x00dev->bands[NL80211_BAND_5GHZ].n_channels =
                    spec->num_channels - 14;
                rt2x00dev->bands[NL80211_BAND_5GHZ].n_bitrates =
                    num_rates - 4;
                rt2x00dev->bands[NL80211_BAND_5GHZ].channels = &channels[14];
                rt2x00dev->bands[NL80211_BAND_5GHZ].bitrates = &rates[4];
                hw->wiphy->bands[NL80211_BAND_5GHZ] =
                    &rt2x00dev->bands[NL80211_BAND_5GHZ];
                memcpy(&rt2x00dev->bands[NL80211_BAND_5GHZ].ht_cap,
                       &spec->ht, sizeof(spec->ht));
        }

        return 0;

 exit_free_channels:
        kfree(channels);
        rt2x00_err(rt2x00dev, "Allocation ieee80211 modes failed\n");
        return -ENOMEM;
}

static void rt2x00lib_remove_hw(struct rt2x00_dev *rt2x00dev)
{
        if (test_bit(DEVICE_STATE_REGISTERED_HW, &rt2x00dev->flags))
                ieee80211_unregister_hw(rt2x00dev->hw);

        if (likely(rt2x00dev->hw->wiphy->bands[NL80211_BAND_2GHZ])) {
                kfree(rt2x00dev->hw->wiphy->bands[NL80211_BAND_2GHZ]->channels);
                kfree(rt2x00dev->hw->wiphy->bands[NL80211_BAND_2GHZ]->bitrates);
                rt2x00dev->hw->wiphy->bands[NL80211_BAND_2GHZ] = NULL;
                rt2x00dev->hw->wiphy->bands[NL80211_BAND_5GHZ] = NULL;
        }

        kfree(rt2x00dev->spec.channels_info);
}

static int rt2x00lib_probe_hw(struct rt2x00_dev *rt2x00dev)
{
        struct hw_mode_spec *spec = &rt2x00dev->spec;
        int status;

        if (test_bit(DEVICE_STATE_REGISTERED_HW, &rt2x00dev->flags))
                return 0;

        /*
         * Initialize HW modes.
         */
        status = rt2x00lib_probe_hw_modes(rt2x00dev, spec);
        if (status)
                return status;

        /*
         * Initialize HW fields.
         */
        rt2x00dev->hw->queues = rt2x00dev->ops->tx_queues;

        /*
         * Initialize extra TX headroom required.
         */
        rt2x00dev->hw->extra_tx_headroom =
                max_t(unsigned int, IEEE80211_TX_STATUS_HEADROOM,
                      rt2x00dev->extra_tx_headroom);

        /*
         * Take TX headroom required for alignment into account.
         */
        if (rt2x00_has_cap_flag(rt2x00dev, REQUIRE_L2PAD))
                rt2x00dev->hw->extra_tx_headroom += RT2X00_L2PAD_SIZE;
        else if (rt2x00_has_cap_flag(rt2x00dev, REQUIRE_DMA))
                rt2x00dev->hw->extra_tx_headroom += RT2X00_ALIGN_SIZE;

        /*
         * Tell mac80211 about the size of our private STA structure.
         */
        rt2x00dev->hw->sta_data_size = sizeof(struct rt2x00_sta);

        /*
         * Allocate tx status FIFO for driver use.
         */
        if (rt2x00_has_cap_flag(rt2x00dev, REQUIRE_TXSTATUS_FIFO)) {
                /*
                 * Allocate the txstatus fifo. In the worst case the tx
                 * status fifo has to hold the tx status of all entries
                 * in all tx queues. Hence, calculate the kfifo size as
                 * tx_queues * entry_num and round up to the nearest
                 * power of 2.
                 */
                int kfifo_size =
                        roundup_pow_of_two(rt2x00dev->ops->tx_queues *
                                           rt2x00dev->tx->limit *
                                           sizeof(u32));

                status = kfifo_alloc(&rt2x00dev->txstatus_fifo, kfifo_size,
                                     GFP_KERNEL);
                if (status)
                        return status;
        }

        /*
         * Initialize tasklets if used by the driver. Tasklets are
         * disabled until the interrupts are turned on. The driver
         * has to handle that.
         */
#define RT2X00_TASKLET_INIT(taskletname) \
        if (rt2x00dev->ops->lib->taskletname) { \
                tasklet_init(&rt2x00dev->taskletname, \
                             rt2x00dev->ops->lib->taskletname, \
                             (unsigned long)rt2x00dev); \
        }

        RT2X00_TASKLET_INIT(txstatus_tasklet);
        RT2X00_TASKLET_INIT(pretbtt_tasklet);
        RT2X00_TASKLET_INIT(tbtt_tasklet);
        RT2X00_TASKLET_INIT(rxdone_tasklet);
        RT2X00_TASKLET_INIT(autowake_tasklet);

#undef RT2X00_TASKLET_INIT

        /*
         * Register HW.
         */
        status = ieee80211_register_hw(rt2x00dev->hw);
        if (status)
                return status;

        set_bit(DEVICE_STATE_REGISTERED_HW, &rt2x00dev->flags);

        return 0;
}

/*
 * Initialization/uninitialization handlers.
 */
static void rt2x00lib_uninitialize(struct rt2x00_dev *rt2x00dev)
{
        if (!test_and_clear_bit(DEVICE_STATE_INITIALIZED, &rt2x00dev->flags))
                return;

        /*
         * Stop rfkill polling.
         */
        if (rt2x00_has_cap_flag(rt2x00dev, REQUIRE_DELAYED_RFKILL))
                rt2x00rfkill_unregister(rt2x00dev);

        /*
         * Allow the HW to uninitialize.
         */
        rt2x00dev->ops->lib->uninitialize(rt2x00dev);

        /*
         * Free allocated queue entries.
         */
        rt2x00queue_uninitialize(rt2x00dev);
}

static int rt2x00lib_initialize(struct rt2x00_dev *rt2x00dev)
{
        int status;

        if (test_bit(DEVICE_STATE_INITIALIZED, &rt2x00dev->flags))
                return 0;

        /*
         * Allocate all queue entries.
         */
        status = rt2x00queue_initialize(rt2x00dev);
        if (status)
                return status;

        /*
         * Initialize the device.
         */
        status = rt2x00dev->ops->lib->initialize(rt2x00dev);
        if (status) {
                rt2x00queue_uninitialize(rt2x00dev);
                return status;
        }

        set_bit(DEVICE_STATE_INITIALIZED, &rt2x00dev->flags);

        /*
         * Start rfkill polling.
         */
        if (rt2x00_has_cap_flag(rt2x00dev, REQUIRE_DELAYED_RFKILL))
                rt2x00rfkill_register(rt2x00dev);

        return 0;
}

int rt2x00lib_start(struct rt2x00_dev *rt2x00dev)
{
        int retval;

        if (test_bit(DEVICE_STATE_STARTED, &rt2x00dev->flags))
                return 0;

        /*
         * If this is the first interface which is added,
         * we should load the firmware now.
         */
        retval = rt2x00lib_load_firmware(rt2x00dev);
        if (retval)
                return retval;

        /*
         * Initialize the device.
         */
        retval = rt2x00lib_initialize(rt2x00dev);
        if (retval)
                return retval;

        rt2x00dev->intf_ap_count = 0;
        rt2x00dev->intf_sta_count = 0;
        rt2x00dev->intf_associated = 0;

        /* Enable the radio */
        retval = rt2x00lib_enable_radio(rt2x00dev);
        if (retval)
                return retval;

        set_bit(DEVICE_STATE_STARTED, &rt2x00dev->flags);

        return 0;
}

void rt2x00lib_stop(struct rt2x00_dev *rt2x00dev)
{
        if (!test_and_clear_bit(DEVICE_STATE_STARTED, &rt2x00dev->flags))
                return;

        /*
         * Perhaps we can add something smarter here,
         * but for now just disabling the radio should do.
         */
        rt2x00lib_disable_radio(rt2x00dev);

        rt2x00dev->intf_ap_count = 0;
        rt2x00dev->intf_sta_count = 0;
        rt2x00dev->intf_associated = 0;
}

static inline void rt2x00lib_set_if_combinations(struct rt2x00_dev *rt2x00dev)
{
        struct ieee80211_iface_limit *if_limit;
        struct ieee80211_iface_combination *if_combination;

        if (rt2x00dev->ops->max_ap_intf < 2)
                return;

        /*
         * Build up AP interface limits structure.
         */
        if_limit = &rt2x00dev->if_limits_ap;
        if_limit->max = rt2x00dev->ops->max_ap_intf;
        if_limit->types = BIT(NL80211_IFTYPE_AP);
#ifdef CONFIG_MAC80211_MESH
        if_limit->types |= BIT(NL80211_IFTYPE_MESH_POINT);
#endif

        /*
         * Build up AP interface combinations structure.
         */
        if_combination = &rt2x00dev->if_combinations[IF_COMB_AP];
        if_combination->limits = if_limit;
        if_combination->n_limits = 1;
        if_combination->max_interfaces = if_limit->max;
        if_combination->num_different_channels = 1;

        /*
         * Finally, specify the possible combinations to mac80211.
         */
        rt2x00dev->hw->wiphy->iface_combinations = rt2x00dev->if_combinations;
        rt2x00dev->hw->wiphy->n_iface_combinations = 1;
}

static unsigned int rt2x00dev_extra_tx_headroom(struct rt2x00_dev *rt2x00dev)
{
        if (WARN_ON(!rt2x00dev->tx))
                return 0;

        if (rt2x00_is_usb(rt2x00dev))
                return rt2x00dev->tx[0].winfo_size + rt2x00dev->tx[0].desc_size;

        return rt2x00dev->tx[0].winfo_size;
}

/*
 * driver allocation handlers.
 */
int rt2x00lib_probe_dev(struct rt2x00_dev *rt2x00dev)
{
        int retval = -ENOMEM;

        /*
         * Set possible interface combinations.
         */
        rt2x00lib_set_if_combinations(rt2x00dev);

        /*
         * Allocate the driver data memory, if necessary.
         */
        if (rt2x00dev->ops->drv_data_size > 0) {
                rt2x00dev->drv_data = kzalloc(rt2x00dev->ops->drv_data_size,
                                              GFP_KERNEL);
                if (!rt2x00dev->drv_data) {
                        retval = -ENOMEM;
                        goto exit;
                }
        }

        spin_lock_init(&rt2x00dev->irqmask_lock);
        mutex_init(&rt2x00dev->csr_mutex);
        mutex_init(&rt2x00dev->conf_mutex);
        INIT_LIST_HEAD(&rt2x00dev->bar_list);
        spin_lock_init(&rt2x00dev->bar_list_lock);
        hrtimer_init(&rt2x00dev->txstatus_timer, CLOCK_MONOTONIC,
                     HRTIMER_MODE_REL);

        set_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags);

        /*
         * Make room for rt2x00_intf inside the per-interface
         * structure ieee80211_vif.
         */
        rt2x00dev->hw->vif_data_size = sizeof(struct rt2x00_intf);

        /*
         * rt2x00 devices can only use the last n bits of the MAC address
         * for virtual interfaces.
         */
        rt2x00dev->hw->wiphy->addr_mask[ETH_ALEN - 1] =
                (rt2x00dev->ops->max_ap_intf - 1);

        /*
         * Initialize work.
         */
        rt2x00dev->workqueue =
            alloc_ordered_workqueue("%s", 0, wiphy_name(rt2x00dev->hw->wiphy));
        if (!rt2x00dev->workqueue) {
                retval = -ENOMEM;
                goto exit;
        }

        INIT_WORK(&rt2x00dev->intf_work, rt2x00lib_intf_scheduled);
        INIT_DELAYED_WORK(&rt2x00dev->autowakeup_work, rt2x00lib_autowakeup);
        INIT_WORK(&rt2x00dev->sleep_work, rt2x00lib_sleep);

        /*
         * Let the driver probe the device to detect the capabilities.
         */
        retval = rt2x00dev->ops->lib->probe_hw(rt2x00dev);
        if (retval) {
                rt2x00_err(rt2x00dev, "Failed to allocate device\n");
                goto exit;
        }

        /*
         * Allocate queue array.
         */
        retval = rt2x00queue_allocate(rt2x00dev);
        if (retval)
                goto exit;

        /* Cache TX headroom value */
        rt2x00dev->extra_tx_headroom = rt2x00dev_extra_tx_headroom(rt2x00dev);

        /*
         * Determine which operating modes are supported, all modes
         * which require beaconing, depend on the availability of
         * beacon entries.
         */
        rt2x00dev->hw->wiphy->interface_modes = BIT(NL80211_IFTYPE_STATION);
        if (rt2x00dev->bcn->limit > 0)
                rt2x00dev->hw->wiphy->interface_modes |=
                    BIT(NL80211_IFTYPE_ADHOC) |
#ifdef CONFIG_MAC80211_MESH
                    BIT(NL80211_IFTYPE_MESH_POINT) |
#endif
#ifdef CONFIG_WIRELESS_WDS
                    BIT(NL80211_IFTYPE_WDS) |
#endif
                    BIT(NL80211_IFTYPE_AP);

        rt2x00dev->hw->wiphy->flags |= WIPHY_FLAG_IBSS_RSN;

        wiphy_ext_feature_set(rt2x00dev->hw->wiphy,
                              NL80211_EXT_FEATURE_CQM_RSSI_LIST);

        /*
         * Initialize ieee80211 structure.
         */
        retval = rt2x00lib_probe_hw(rt2x00dev);
        if (retval) {
                rt2x00_err(rt2x00dev, "Failed to initialize hw\n");
                goto exit;
        }

        /*
         * Register extra components.
         */
        rt2x00link_register(rt2x00dev);
        rt2x00leds_register(rt2x00dev);
        rt2x00debug_register(rt2x00dev);

        /*
         * Start rfkill polling.
         */
        if (!rt2x00_has_cap_flag(rt2x00dev, REQUIRE_DELAYED_RFKILL))
                rt2x00rfkill_register(rt2x00dev);

        return 0;

exit:
        rt2x00lib_remove_dev(rt2x00dev);

        return retval;
}
EXPORT_SYMBOL_GPL(rt2x00lib_probe_dev);

void rt2x00lib_remove_dev(struct rt2x00_dev *rt2x00dev)
{
        clear_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags);

        /*
         * Stop rfkill polling.
         */
        if (!rt2x00_has_cap_flag(rt2x00dev, REQUIRE_DELAYED_RFKILL))
                rt2x00rfkill_unregister(rt2x00dev);

        /*
         * Disable radio.
         */
        rt2x00lib_disable_radio(rt2x00dev);

        /*
         * Stop all work.
         */
        cancel_work_sync(&rt2x00dev->intf_work);
        cancel_delayed_work_sync(&rt2x00dev->autowakeup_work);
        cancel_work_sync(&rt2x00dev->sleep_work);

        hrtimer_cancel(&rt2x00dev->txstatus_timer);

        /*
         * Kill the tx status tasklet.
         */
        tasklet_kill(&rt2x00dev->txstatus_tasklet);
        tasklet_kill(&rt2x00dev->pretbtt_tasklet);
        tasklet_kill(&rt2x00dev->tbtt_tasklet);
        tasklet_kill(&rt2x00dev->rxdone_tasklet);
        tasklet_kill(&rt2x00dev->autowake_tasklet);

        /*
         * Uninitialize device.
         */
        rt2x00lib_uninitialize(rt2x00dev);

        if (rt2x00dev->workqueue)
                destroy_workqueue(rt2x00dev->workqueue);

        /*
         * Free the tx status fifo.
         */
        kfifo_free(&rt2x00dev->txstatus_fifo);

        /*
         * Free extra components
         */
        rt2x00debug_deregister(rt2x00dev);
        rt2x00leds_unregister(rt2x00dev);

        /*
         * Free ieee80211_hw memory.
         */
        rt2x00lib_remove_hw(rt2x00dev);

        /*
         * Free firmware image.
         */
        rt2x00lib_free_firmware(rt2x00dev);

        /*
         * Free queue structures.
         */
        rt2x00queue_free(rt2x00dev);

        /*
         * Free the driver data.
         */
        kfree(rt2x00dev->drv_data);
}
EXPORT_SYMBOL_GPL(rt2x00lib_remove_dev);

/*
 * Device state handlers
 */
#ifdef CONFIG_PM
int rt2x00lib_suspend(struct rt2x00_dev *rt2x00dev, pm_message_t state)
{
        rt2x00_dbg(rt2x00dev, "Going to sleep\n");

        /*
         * Prevent mac80211 from accessing driver while suspended.
         */
        if (!test_and_clear_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags))
                return 0;

        /*
         * Cleanup as much as possible.
         */
        rt2x00lib_uninitialize(rt2x00dev);

        /*
         * Suspend/disable extra components.
         */
        rt2x00leds_suspend(rt2x00dev);
        rt2x00debug_deregister(rt2x00dev);

        /*
         * Set device mode to sleep for power management,
         * on some hardware this call seems to consistently fail.
         * From the specifications it is hard to tell why it fails,
         * and if this is a "bad thing".
         * Overall it is safe to just ignore the failure and
         * continue suspending. The only downside is that the
         * device will not be in optimal power save mode, but with
         * the radio and the other components already disabled the
         * device is as good as disabled.
         */
        if (rt2x00dev->ops->lib->set_device_state(rt2x00dev, STATE_SLEEP))
                rt2x00_warn(rt2x00dev, "Device failed to enter sleep state, continue suspending\n");

        return 0;
}
EXPORT_SYMBOL_GPL(rt2x00lib_suspend);

int rt2x00lib_resume(struct rt2x00_dev *rt2x00dev)
{
        rt2x00_dbg(rt2x00dev, "Waking up\n");

        /*
         * Restore/enable extra components.
         */
        rt2x00debug_register(rt2x00dev);
        rt2x00leds_resume(rt2x00dev);

        /*
         * We are ready again to receive requests from mac80211.
         */
        set_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags);

        return 0;
}
EXPORT_SYMBOL_GPL(rt2x00lib_resume);
#endif /* CONFIG_PM */

/*
 * rt2x00lib module information.
 */
MODULE_AUTHOR(DRV_PROJECT);
MODULE_VERSION(DRV_VERSION);
MODULE_DESCRIPTION("rt2x00 library");
MODULE_LICENSE("GPL");